Question

a) x2 -12x + 20 = 0 ????

Answer 1

Resposta:

x² - 20 = 0

x² = 20

x = ±√20

x'= √20

x"= -√20

Answer 2

x² - 12x + 20 = 0

a = 1. b = - 12. c = 20

∆ = b² - 4 . a . c

∆ = (-12)² - 4 . 1 . 20

∆ = 144 - 80

∆ = 64

x = - b ± √∆

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2a

x' = -(-12) - 8

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2 . 1

x' = 12 - 8

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2

x' = 4

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2

x' = 2

x" = -(-12) + 8

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2 . 1

x" = 12 + 8

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2

x" = 20

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2

x" = 10

S = {2, 10}